A small plane clipped the top of a store before it crashed in the parking lot of a San Diego shopping center, killing an 80-year-old passenger and seriously injuring the 52-year-old pilot, authorities said.

As the search for a missing Marine wife nears the three-week mark, a witness now says he watched the pregnant Erin Corwin rendezvous and depart with another man from the site where her abandoned vehicle later turned up.

Recalling how he first alerted state police after his group, on horseback, encountered DiMaggio and Anderson in rugged backcountry on Wednesday, Mark John, a retired Gem County, Idaho, sheriff, conceded it was his wife who intuited that the girl might be in trouble.

"You know, when we were on the lake, my wife wanted to talk to the girl … she felt something might be wrong, and I said, 'No, it might be a lovers' quarrel,' " John told reporters on Sunday.

He and his wife noted that, as they rode away from seeing the couple, Hannah said aloud to herself, "Looks like we're in real trouble now."